21 May 2003
A process that welds thermoplastics and leaves an invisible joint is finding its first commercial applications in Europe.
At the heart of the patented process are specially-developed infrared-absorbing inks. These are applied to the surfaces to be welded. When illuminated by a diode or Nd:YAG laser they convert infrared laser light into heat at the interface between the pieces, creating a uniform colourless weld.
According to Gareth McGrath, the former head of TWI's Polymer Technology Group who recently joined Gentex as its European business development manager, the first big application area is the fabrication of ink-jet reservoirs for computer printers.
"These are actually going into production at the moment," said McGrath. "Ink-jet reservoirs are actually quite a difficult part to manufacture. If you bond them using adhesives, the solvent and the inks tend to affect the join so welding it is a tremendous opportunity."
Although Clearweld has also joined certain artificial textiles to make shirts and fleeces, McGrath is more excited about its future prospects for making medical parts where high quality, hermetic packaging is critical.
"We believe the real success story lies in the medical sector," he commented. "There are many opportunities to change the manufacturing process and make it more reliable and lower-cost."
As well as offering contract-manufacturing services, Gentex is selling the inks to interested customers and is in the process of signing strategic partnerships to help market them. To date, 12 different inks are commercially available for use with a range of different plastics. Each has a peak absorption centred at 940 nm and suits use with either a laser diode or a Nd:YAG source.
Oliver Graydon is editor of Optics.org and Opto & Laser Europe magazine.